1. Field of the Invention
This invention is directed to a biomedical blood collection device, and, in certain aspects, to laser devices for the collection of capillary blood and/or interstitial fluid. In one aspect this invention is directed to systems for protecting optical and mechanical components from the effects of the byproducts of laser ablation of skin.
2. Description of Related Art
Certain prior art laser skin perforation devices use a pulse or pulses of laser light, generally infrared laser light, to ablate a small hole in the skin of a patient to a depth sufficient to cause bleeding. Small samples of capillary blood may be collected from such small holes for chemical or physical analysis of the blood. International Patent Application No. PCT/US93/10279 discloses certain aspects of laser skin perforation and subsequent capillary blood collection and discusses the potential use of disposable devices for collection of the capillary blood elicited as a result of the procedure.
During the laser perforation process a volume of skin tissue is vaporized by laser energy projected onto the skin surface. The laser energy causes very rapid and explosive heating of the tissue resulting in the formation of a small wound. Ablation gasses are expelled from the wound carrying tissue byproducts. Such expulsion may occur at supersonic speeds such that a popping noise may also be apparent. Ablation gasses may also be heated to the point of luminescence, causing a flash of light to arise from the skin surface. The capillary blood collection procedure is often performed by perforating the fingertips of adult and juvenile patients or by perforating the heels of infant patients.
There are certain negative aspects of certain prior art laser perforation procedures which are a detriment to the performance of perforator devices and to commercial acceptability and success. One such aspect is the expulsion of tissue detritus which may settle onto the surface of a laser lens, reducing the transmissivity of optics and thus requiring frequent cleaning or replacement of the lens. Further, the settling of such detritus on a laser instrument may provide an opportunity for infectious disease transmission when the device is subsequently used by another patient.
Another negative aspect of certain prior art skin perforation procedures is the production of noise and light as a result of skin ablation. These effects may produce undue apprehension in patients experiencing the procedure.
Yet another negative aspect of certain prior art procedures is the possibility that, if blood is spontaneously elicited from the wound as a result of the procedure, such blood may be deposited on the surface of the laser device presenting an opportunity for infectious disease transmission when the device is subsequently used by another patient.
There is, therefore, a need for creating safe, easily replaceable or disposable devices which will serve to minimize these detrimental effects of the laser skin perforation procedure.